Re: Don't Try This

        Re: Don't Try This
        Tue, 8 Apr 1997 04:49:35 -0700
        "DR.RESONANCE" <DR.RESONANCE-at-next-wave-dot-net>
        "Tesla List" <tesla-at-poodle.pupman-dot-com>


The device you have created is not a Tesla coil.  It is called a
Cockraft-Walton voltage multiplier.  It was first used to develop 600 KV
back in 1939 to achieve the first atomic transmutation of the element
lithium.  It is similar to a Marx generator but different in a few
It can provide a continuous and well regulated output, and it does not
sparkgaps as switches -- the diodes act as high speed switches to
the caps in series.

It was developed by a Mr. Cockraft and Mr. Walton and named in their

If you repair your unit I suggest wiring a 500K 20 watt resistor in
with the output.  Also used another dampening device such as a 500
microHenry inductor -- also in series with the output.  That will keep
diodes from frying in the event of any short circuit.

Good luck and be careful -- charged HV caps are killers.  Even when
discharged end to end the center caps in the group will still retain
charge to zap you --- I also discovered this the hard way in my younger
days.   Yes --- coilin' is safer.


> From: Tesla List <tesla-at-poodle.pupman-dot-com>
> To: tesla-at-poodle.pupman-dot-com
> Subject: Don't Try This
> Date: Sunday,April 06,1997 5:54 PM
> Subject: 
>         Don't Try This
>   Date: 
>         Sun, 06 Apr 1997 12:54:02 -0700
>   From: 
>         Gary Weaver <gweaver-at-earthlink-dot-net>
>     To: 
>         tesla-at-pupman-dot-com
> Today while going threw some old papers I found a Xerox copy of a Tesla
> Coil 
> that uses a voltage multiplyer instead of a neon transformer.  It uses
> 10 
> diodes and 10 capacitors.  The diodes are 1N4007 and the caps are .001
> uf 
> 1000 volts.  The circuit suggests using an old TV transformer about 800 
> volts for the voltage multiplyer circuit. The voltage multiplyer
> discharges 
> threw the spark gap across the LC circuit and the secondary coil output
> is 
> suppost to be 8" to 10". 
> I decided to build it and try it.  If it works I will build the TC into
> a 
> nice little unit and put it on my desk at work. I looked threw my parts
> and 
> couldn't find any .001 uf 1000 volt capacitors to used in the voltage 
> multipler circuit so I used 4700 MFD 200 volt capacitors.  I figured it
> won't 
> work with these caps but it will be fun to experement with anyway. I put
> a 
> volt meter on the 1st of the 10 capacitors and a 200 ohm 20 watt current 
> limiting resistor in the 120 volt AC line.  I plugged it into the wall
> and it 
> took several minutes to come up to full charge.  Now I know this won't
> work 
> for a Tesla Coil.
> I unplugged the wire.  I decided not to leave the capacitor bank setting
> on 
> the work bench with a full charge.  I decided to discharge the
> capacitors 
> threw the 200 ohm 2 watt current limiting resistor connected on the
> output. I 
> checked the resistor with the multi meter and it checked about 200 ohms.
> When 
> I connected the resistor to the output it discharged all the capacitors
> in a 
> micro second.  BOOM...........WOW, what a discharge.  
> The 200 ohms 2 watt resistor looks like a piece of charcoal. The
> resistor is 
> still there but it is fryed.  All the diodes are gone except for the
> wires 
> that use to be part of the diodes.  The end of the capacitors all have
> burned 
> spots from the diodes that exploded.
> Gary Weaver